Abstract: Derailleur with at least two sprockets on a sprocket set which is located around a pedal axle of a bicycle, which sprockets are provided with chain transfer assistance measures to assist the transfer of the chain in upshifting or downshifting, whereby the shifting can be done under load in both of these directions. The chain transfer assistance measures comprise a tooth space with a spiral-shaped base, a conical rivet with an encircling sharp edge to locate the chain in the vicinity of its links between the chain plates, as well as bevels, recesses and steps, the totality of which optimize the chain transfer in both directions between sprockets which are coordinated with one another.

Abstract: A rod guide for use with a rotating progressing cavity pump rod string which minimizes the resistance offered thereby to the axial flow of well fluids. This rod guide decreases turbulence and thereby reduces internal abrasion of the rod and tubing wear together with energy demand. The helical guide may employ either one or two lead vanes.

Abstract: A gear shifting system for use on a derailleur equipped bicycle having automatic and manual modes of operation. A microcontroller is mounted to the bicycle frame. Sensors are also mounted to the frame to allow the microcontroller to determine the most efficient gear ratio based on the bicycle velocity and the user pedaling rate in the automatic mode of operation. Servomotors mounted to the bicycle frame are responsive to the outputs to drive the bicycle derailleur and provide the most efficient gear ratio. A control panel mounted to the bicycle handlebars allows the user to select either the automatic or manual operating mode, the latter allowing manual activation of the gear shifters through the microcontroller and servomotors. The microcontroller has at least two input capture functions responsive to bicycle velocity and the cadence, in the automatic mode, and two output compare functions which adjust the derailleurs accordingly.